I learned everything I needed to know about Donald Trump years ago when an environmental organization whose Board I chaired opposed his plan to build gated gilded skyscrapers on the Hudson River waterfront, blocking views and waterfront access for the rest of the citizens. He wrote me a letter in which he stated that his new buildings would be terrific, that if we withdrew our opposition we would receive a great contribution, and that if we didn’t he would destroy us. Sound familiar? The art of the deal.

So now “Trump First” has morphed into “America First” and European leaders last week were on the receiving end of the only way of behaving the man knows.

A few things are notable about the trip. After only five months of Trumpism, U.S. foreign policy has ceased to exist. Since the end of World War II U.S. foreign policy has reflected a complex vectoring of national security, commercial, ideological, and political objectives. The official positions of the U.S. government emerged and evolved from a broad and inclusive process played out within the framework of a professional State Department and national security staff, the constitutional role of Congress, the limitations of multilateral and bilateral commitments, and the participation of a wide variety of private sector and political interests. Today, U.S. foreign policy appears to be whatever slogan pops into the head of a single spectacularly ill-informed man, who exists in a cocoon of ideologues and billionaires, does not read or absorb briefings, and has ignored and marginalized the entire foreign policy establishment. “I alone,” he says, will decide.

Imagine what they were thinking. The leaders of Europe, all sophisticated, serious, informed, briefed. All facing critical challenges such as the future of the EU, the refugee crisis, climate change, and the terrifying specter of a newly assertive Russia. Now the door closes and they are alone with Trump, one moment behaving like a star struck B-lister giddy with excitement that he’s reached these rarefied heights, and the next moment a sneering bully, compensating for his ignorance and insecurity with aggression and bombast. Even the Wall Street Journal called his behavior on the trip “undiplomatic, and sometimes rude,” “embarrassing for most Americans,” and “dangerous.” And that from a conservative publication that attempts daily to put a positive spin on each day’s debacle.

So there they are, the leaders of Europe. For 60 years they relied on their U.S. ally as the bulwark against a repeat of the catastrophic 20th century. And now: NATO is obsolete (maybe, depends on who he spoke to last), extortionate threats that the US will not fulfill its mutual defense commitments unless they pay up (at the end of the day it’s all just about money, right?), and abandonment of generations of GOP and American support for free trade. After all, who cares about all these foreigners, since “from this day forward, it’s going to be only America first, America first.”

Is it any surprise that Angela Merkel, citing “what I experienced in recent days,” uttered the obvious? Europe can no longer rely on America. Welcome to the club, Angela. America can no longer rely on America.